Yes, you should declare it — but how depends on the source of investment:
✅ If you bought the plot from your own funds: In your Wealth Statement, you must show it as an asset under spouse’s name (gifted/benami entry). You’ll also show a corresponding gift/transfer in your “outflows” section, so your wealth reconciles.
✅ If your wife bought it from her own taxable income: Then she must declare it in her own Wealth Statement/Return, not you.
In short: Whoever provided the money must reflect it in their return, while the person in whose name the property is registered must also show ownership if they are a filer.